It seems that in the European capitals, many powers were stunned by the quick German victory and taken by surprise. Interestingly, Bismarck wanted Italy to take Nice and Savoy back. His hope was to reduce France as a great power. On 27 July 1870 he did state that he saw an "advantage from seeing Italy's power increased". Giuseppe Mazzini in May of 1871 did press the Italians to take Nice and Savoy. Also, in March of 1871 a delegation of Corsicans arrived in Florence to meet with Italian deputies hoping to be incorporated into the new Italy. If Italy wants to begin colonial expansion, they can take the department of Constantine in Algeria. It had more Italians and Maltese than French Europeans.
As for Spain, the country was probably in too much turmoil at the time to even fathom intervening. In late November of 1870, Amadeo the Duke of Aosta arrived in Cartagena as the new King. Amadeo was not a very popular king at first, so perhaps to drum up popular support he enters the war against France in December. The French were all but defeated by that time, and it could be a good way for Amadeo to get the support of the conservatives. Oran would probably be the main target, if they could take that portion of Algeria. If they're really expansionist, they partition Algeria with Italy and take Algiers too, there were fewer than 90,000 French in Algeria at the time, so it shouldn't be too difficult. Perhaps Roussillon too, as it had been part of Catalonia.